I recently had a leak in my bathroom that led to a lot of mold. I am in the process of tearing down drywall/insulation and replacing.

One of the pockets between the studs has water pipes (hot & cold). Is it safe to put insulation in this area touching the pipes? I noticed that there is no insulation in this section of the wall, so I am hesitant to put it there.

The insulation I bought from Lowes is fiberglass that is wrapped in plastic (instead of being faced with paper). It said this was more resistant to water and safer to handle than the paper-faced kind.

If you are concerned about water condensation on the cold water pipe you can use foam water pipe insulation that is slit so that when it is cut to fit a length of installed pipe, it can be pushed to snap around the pipe.

If you are worried about the hot pipe melting the plastic facer, either 1. quit worrying, because the temp on the pipe isn't hot enough, or 2. insulate the pipes with foam pipe insulation, or 3. cut the fiberglass around the pipes, or 4. do #2 and 3, which is the way it should be done.

RegeSullivan

10-06-2009 08:32 AM

If you are in a climate that gets well below freezing only insulate behind the pipe, between the pipe and the outside wall. You might want to use ridged foam insulation and spray foam. It will solve any problems you might have with occasional condensation and allow you to stop most air infiltration. The insulation can be touching the back of the pipe or even go half way around it as long as it is exposed to the inside wall. Insulating between the pipe and the inside wall can allow the pipe to freeze in very cold weather.

If you are in a warm climate where the temp never goes much below freezing use foam pipe insulation and insulate in the wall as you normally would.